diff --git a/package/Snippets/variable.sublime-snippet b/package/Snippets/variable.sublime-snippet
index e45a58a..e285d84 100644
--- a/package/Snippets/variable.sublime-snippet
+++ b/package/Snippets/variable.sublime-snippet
@@ -1,5 +1,5 @@
 <snippet>
-	<content><![CDATA[let ${1:name}: ${2:type} = ${0:value};]]></content>
+	<content><![CDATA[let ${1:name}${2:: type} = ${0:value};]]></content>
 	<tabTrigger>variable</tabTrigger>
 	<scope>source.tact</scope>
 	<description>let …: … = …;</description>
diff --git a/package/Tact.sublime-completions b/package/Tact.sublime-completions
index a23ef1f..79d4cff 100644
--- a/package/Tact.sublime-completions
+++ b/package/Tact.sublime-completions
@@ -633,10 +633,10 @@
             "details": "<a href=\"https://docs.tact-lang.org/ref/core-debug#nativethrow\">Tact Docs</a>"
         },
         {
-            "trigger": "nativeThrowWhen\tthrow exit code under condition",
-            "contents": "nativeThrowWhen(${1:code_Int}, ${2:condition_Bool})",
+            "trigger": "nativeThrowIf\tthrow exit code under condition",
+            "contents": "nativeThrowIf(${1:code_Int}, ${2:condition_Bool})",
             "kind": "function",
-            "details": "<a href=\"https://docs.tact-lang.org/ref/core-debug#nativethrowwhen\">Tact Docs</a>"
+            "details": "<a href=\"https://docs.tact-lang.org/ref/core-debug#nativethrowif\">Tact Docs</a>"
         },
         {
             "trigger": "nativeThrowUnless\tthrow exit code unless condition",
diff --git a/package/Tact.tmLanguage b/package/Tact.tmLanguage
index fa5080b..194e86e 100644
--- a/package/Tact.tmLanguage
+++ b/package/Tact.tmLanguage
@@ -725,7 +725,7 @@
             <key>comment</key>
             <string>Control flow keywords, prefixed by more than one dot</string>
             <key>match</key>
-            <string>(?&lt;=\.\.)\b(else|catch|until|in)\b</string>
+            <string>(?&lt;=\.\.)\b(else|catch|until|in(?!\s*\())\b</string>
             <key>name</key>
             <string>keyword.control.tact</string>
           </dict>
@@ -733,7 +733,7 @@
             <key>comment</key>
             <string>Control flow keywords</string>
             <key>match</key>
-            <string>(?&lt;!\.)\b(if|else|try|catch|repeat|do|until|while|foreach|in|return)\b</string>
+            <string>(?&lt;!\.)\b(if|else|try|catch|repeat|do|until|while|foreach|in(?!\s*\()|return)\b</string>
             <key>name</key>
             <string>keyword.control.tact</string>
           </dict>
@@ -849,12 +849,25 @@
       </dict>
       <key>variable</key>
       <dict>
-        <key>comment</key>
-        <string>Any valid Tact identifier</string>
-        <key>match</key>
-        <string>\b([a-zA-Z_][a-zA-Z0-9_]*)\b</string>
-        <key>name</key>
-        <string>variable.other.tact</string>
+        <key>patterns</key>
+        <array>
+          <dict>
+            <key>comment</key>
+            <string>Any valid Tact identifier</string>
+            <key>match</key>
+            <string>(?&lt;!\.)\b(_)\b</string>
+            <key>name</key>
+            <string>comment.unused-identifier.tact</string>
+          </dict>
+          <dict>
+            <key>comment</key>
+            <string>Any valid Tact identifier</string>
+            <key>match</key>
+            <string>\b([a-zA-Z_][a-zA-Z0-9_]*)\b</string>
+            <key>name</key>
+            <string>variable.other.tact</string>
+          </dict>
+        </array>
       </dict>
     </dict>
   </dict>
diff --git a/package/Tact.tmLanguage.json b/package/Tact.tmLanguage.json
index 6db90b0..615ef7d 100644
--- a/package/Tact.tmLanguage.json
+++ b/package/Tact.tmLanguage.json
@@ -475,12 +475,12 @@
           },
           {
             "comment": "Control flow keywords, prefixed by more than one dot",
-            "match": "(?<=\\.\\.)\\b(else|catch|until|in)\\b",
+            "match": "(?<=\\.\\.)\\b(else|catch|until|in(?!\\s*\\())\\b",
             "name": "keyword.control.tact"
           },
           {
             "comment": "Control flow keywords",
-            "match": "(?<!\\.)\\b(if|else|try|catch|repeat|do|until|while|foreach|in|return)\\b",
+            "match": "(?<!\\.)\\b(if|else|try|catch|repeat|do|until|while|foreach|in(?!\\s*\\()|return)\\b",
             "name": "keyword.control.tact"
           },
           {
@@ -556,9 +556,18 @@
       },
 
       "variable": {
-        "comment": "Any valid Tact identifier",
-        "match": "\\b([a-zA-Z_][a-zA-Z0-9_]*)\\b",
-        "name": "variable.other.tact"
+        "patterns": [
+          {
+            "comment": "Any valid Tact identifier",
+            "match": "(?<!\\.)\\b(_)\\b",
+            "name": "comment.unused-identifier.tact"
+          },
+          {
+            "comment": "Any valid Tact identifier",
+            "match": "\\b([a-zA-Z_][a-zA-Z0-9_]*)\\b",
+            "name": "variable.other.tact"
+          }
+        ]
       }
     }
   }
diff --git a/tests/syntax_test_statement.tact b/tests/syntax_test_statement.tact
index 2ee87cc..67a4c1e 100644
--- a/tests/syntax_test_statement.tact
+++ b/tests/syntax_test_statement.tact
@@ -52,6 +52,9 @@ extends fun c(self: SomeMessage): Int {
         // ^^ keyword.operator.assignment.tact
         //    ^^ constant.numeric.decimal.tact
         //      ^ punctuation.semi.tact
+
+        let _ = 20;
+        //  ^ comment.unused-identifier.tact
     }
 
     self.description = "Tact is awesome!";